It is proposed to continue our studies on the significance and role that poly-prenylpyophosphates play in the alkylation of aromatic compounds by mammalian tissues. Previous work has shown that P-aminobenzoate is alkylated by P-hydroxybenzoate polyprenyl transferase. These studies have been extended to a variety of other aromatic nuclei of biological significance especially those related to metabolites of catecholamines. The significance of the presence of polyprenylpyrophosphates in mitochondrial membranes and the role they play in mitochondrial processes is being investigated. Purification and delineation of the characteristics of the enzymes involved is also planned. It has been observed that agents which affect the state of mitochrondrial membranes exert profound effects on these enzyme processes.